Frontline did a decent piece on them.

You can also use a large plate the same way.

Not too far fetched. Many vaccines are made with surface proteins from viruses that can be recognized by the immune system. But my guess is going through the pasteurization most proteins would be denatured and not in the functional form.

https://www.chop.edu/centers-programs/vaccine-education-center/making-vaccines/how-are-vaccines-made

And why it’s important to the Russian population.

“During Navalny’s funeral, people realized that they are many and that there’s a way for them to show that their opinion counts,” Duntsova, the barred presidential hopeful, told POLITICO. “In today’s Russia, queues have become a symbol of dissent, a way to express your civic position.”